The present invention relates to a sleep posture alerting apparatus, comprising                an electronic control unit,        a body posture detecting sensor operatively connected to the control unit for detecting the posture of the body, and        an alarming device operatively connected to the control unit,wherein, the sleep posture alerting device has a normal operational mode, in which—when the posture of the body detected by the sensor exits a predefined posture range—the control unit sends an alarm signal to the alarm device, and the alarming device generates an alarm based on the signal received from the control unit, to alert said person.        
Such an apparatus is disclosed in WO 2011/139141.
It is an object of the invention to provide an improved sleep posture alerting apparatus.